Liquid crystalline fluorine-containing cyclohexylbiphenyls and dielectrics and electro-optical display elements based thereon

Abstract

A Cyclohexylbiphenyl of the formula ##STR1## wherein R 1 is alkyl of 1-12 C atoms; R 6 is alkyl or alkoxy each of 1-12 C atoms, CN or fluorine; and R 2 , R 3 , R 4 and R 5 each is hydrogen or fluorine, with the proviso that at least one, but not more than two of R 2 , R 3 , R 4 , R 5 and R 6 are fluorine.

We claim: 
     
       1. A cyclohexylbiphenyl of the formula ##STR10## wherein R 1  is alkyl of 1-12 C atoms; R 6  is alkyl or alkoxy each of 1-12 C atoms, CN or fluorine; and R 2 , R 3 , R 4  and R 5  each is hydrogen or fluorine, with the proviso that at least one of R 4  and R 5  is fluorine, but not more than two of R 2 , R 3 , R 4 , R 5  and R 6  are fluorine. 
     
     
       2. A compound of claim 1 of the formula ##STR11## wherein R 1  is alkyl of 1-12 C atoms and R 7  is alkyl or alkoxy of 1-12 C atoms or CN. 
     
     
       3. A compound of claim 1 of the formula ##STR12## wherein R 1  is alkyl of 1-12 C atoms. 
     
     
       4. A compound of claim 1 of the formula ##STR13## wherein R 1  is alkyl of 1-12 C atoms and R 7  is alkyl or alkoxy of 1-12 C atoms or CN. 
     
     
       5. A liquid-crystalline dielectric comprising two or more liquid-crystalline components, wherein at least one component is a cyclohexylbiphenyl of claim 1. 
     
     
       6. A liquid-crystalline dielectric of claim 5 wherein the amount of the cyclohexylbiphenyl is up to 50 wt. percent. 
     
     
       7. An electro-optical display element having a liquid crystal cell comprising a liquid-crystalline dielectric of claim 5. 
     
     
       8. A compound of claim 1 wherein R 2  and R 3  are each hydrogen.